<template>
  <div class="goods" id="goods" name="goods">
    <!-- 面包屑 -->
    <div class="breadcrumb">
      <el-breadcrumb separator-class="el-icon-arrow-right">
        <el-breadcrumb-item to="/">首页</el-breadcrumb-item>
        <el-breadcrumb-item>全部商品</el-breadcrumb-item>
        <el-breadcrumb-item v-if="search">搜索</el-breadcrumb-item>
        <el-breadcrumb-item v-else>分类</el-breadcrumb-item>
        <el-breadcrumb-item v-if="search">{{search}}</el-breadcrumb-item>
      </el-breadcrumb>
    </div>
    <!-- 面包屑END -->

    <!-- 分类标签 -->
    <div class="nav">
      <div class="product-nav">
        <div class="title">分类</div>
        <el-tabs v-model="activeName" type="card">
          <el-tab-pane
            v-for="item in categoryList"
            :key="item.category_id"
            :label="item.category_name"
            :name="''+item.category_id"
          />
        </el-tabs>
      </div>
    </div>
    <!-- 分类标签END -->

    <!-- 主要内容区 -->
    <div class="main">
      <div class="list">
        <MyList :list="product" v-if="product.length>0"></MyList>
        <div v-else class="none-product">抱歉没有找到相关的商品，请看看其他的商品</div>
      </div>
      <!-- 分页 -->
      <div class="pagination">
        <el-pagination
          background
          layout="prev, pager, next"
          :page-size="pageSize"
          :total="total"
          @current-change="currentChange"
        ></el-pagination>
      </div>
      <!-- 分页END -->
    </div>
    <!-- 主要内容区END -->
  </div>
</template>

<script>
  import cate from "@/data/3.json";
  import allProduct from "@/data/4.json";
  import MyList from '@/components/MyList';

  export default {
    name: "Goods",
    components:{
      MyList
    },
    data() {
      return {
        categoryList: "", //分类列表
        categoryID: [], // 分类id
        product: "", // 商品列表
        productList: "",
        total: 0, // 商品总量
        pageSize: 15, // 每页显示的商品数量
        currentPage: 1, //当前页码
        activeName: "-1", // 分类列表当前选中的id
        search: "", // 搜索条件
        allProduct: allProduct
      };
    },
    created() {
      // 获取分类列表
      const val = {
        category_id: 0,
        category_name: "全部"
      };
      const cateList = [...cate.category];
      cateList.unshift(val);
      this.categoryList = cateList;
      this.activeName = "0";
    },
    watch: {
      // 监听点击了哪个分类标签，通过修改分类id，响应相应的商品
      activeName: function (val) {
        if (Number(val) === 0) {
          this.categoryID = [];
        }
        if (val > 0) {
          this.categoryID = [Number(val)];
        }
        // 初始化商品总量和当前页码
        this.total = 0;
        this.currentPage = 1;
        // 更新地址栏链接，方便刷新页面可以回到原来的页面
        this.$router.push({
          path: "/xiaomi/goods",
          query: {categoryID: this.categoryID}
        });
      },
      // 监听分类id，响应相应的商品
      categoryID: function () {
        this.getData();
        this.search = "";
      }
    },
    methods: {
      // 返回顶部
      backtop() {
        const timer = setInterval(function () {
          const top = document.documentElement.scrollTop || document.body.scrollTop;
          const speed = Math.floor(-top / 5);
          document.documentElement.scrollTop = document.body.scrollTop = top + speed;
          if (top === 0) {
            clearInterval(timer);
          }
        }, 20);
      },
      // 页码变化调用currentChange方法
      currentChange(currentPage) {
        this.currentPage = currentPage;
        if (this.search != "") {
          this.getProductBySearch();
        } else {
          this.getData();
        }
        this.backtop();
      },
      // 向后端请求全部商品或分类商品数据
      getData() {
        console.log(this.currentPage);

        // 如果分类列表为空则请求全部商品数据，否则请求分类商品数据
        if (this.categoryID.length === 0) {
          this.product = allProduct.Product;
          this.total = allProduct.total;
        } else {
          // 处理分类的过滤
          let cateId = Number(this.categoryID[0]);
          let result = {
            Product: [],
            total: 0
          };
          allProduct.Product.forEach((item) => {
            if (item.category_id === cateId) {
              result.Product.push(item);
              result.total = result.total + 1;
            }
          });
          this.product = result.Product;
          this.total = result.total;
        }

      }
    }
  };
</script>

<style scoped>
  .goods {
    background-color: #f5f5f5;
  }

  /* 面包屑CSS */
  .el-tabs--card .el-tabs__header {
    border-bottom: none;
  }

  .goods .breadcrumb {
    height: 50px;
    background-color: white;
  }

  .goods .breadcrumb .el-breadcrumb {
    width: 1225px;
    line-height: 30px;
    font-size: 16px;
    margin: 0 auto;
  }

  /* 面包屑CSS END */

  /* 分类标签CSS */
  .goods .nav {
    background-color: white;
  }

  .goods .nav .product-nav {
    width: 1225px;
    height: 40px;
    line-height: 40px;
    margin: 0 auto;
  }

  .nav .product-nav .title {
    width: 50px;
    font-size: 16px;
    font-weight: 700;
    float: left;
  }

  /* 分类标签CSS END */

  /* 主要内容区CSS */
  .goods .main {
    margin: 0 auto;
    max-width: 1225px;
  }

  .goods .main .list {
    min-height: 650px;
    padding-top: 14.5px;
    margin-left: -13.7px;
    overflow: auto;
  }

  .goods .main .pagination {
    height: 50px;
    text-align: center;
  }

  .goods .main .none-product {
    color: #333;
    margin-left: 13.7px;
  }

  /* 主要内容区CSS END */
</style>
